Merge "Drop supplementary groups for child zygotes." into rvc-dev am:...

Merge "Drop supplementary groups for child zygotes." into rvc-dev am: 1a081317 am: 0a5d18b0 am: 25a4aa7f am: ed19e505

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/11691823

Change-Id: Id41eb9da543ef9963e3bd86c78a1db90e6df865b